Conventional steel or stainless steel gratings for windows/doors as shown in FIG. 1 usually consists of a plurality of crossed steel or stainless steel strips. Such strips are first twisted at predetermined points and are then joined by drilling a small hole at desired intersection to allow a rivet to pass therethrough and fastens the intersected strips together. To twist and drill the strips, marks for this purpose are required. The strips are twisted so that they are turned 90 degrees between two holes. To rivet together the strips, hammer and anvil as well as other tools are possibly required to help the riveting. Therefore, the fabrication and manufacture of conventional steel or stainless steel gratings for windows/doors as shown in FIG. 1 is laborious and time-consuming. Moreover, the strips are not twisted and drilled so precisely that the fabricated strips may not be fitly and successfully riveted together through the holes drilled.
FIG. 2 illustrates another type of conventional stainless steel gratings for windows/doors, in which stainless steel flat strips for horizontal members and round bars for vertical members are combined. Small holes have to be drilled on the flat strips for the round bars to fitly pass through. Again, any deviation in position of the drilled holes or any crook of the strips will easily hinder the successful engagement of the round bars with the flat strips through the holes. The manufacture and assembly of such Gratings is inconvenient (time-consuming and labor-consuming). Moreover, the drilled flat strips shall have narrowed margins and accordingly, reduced strength and are easily broken from outcoming forces. The assembled flat strips and round bars tend to loosen at the joints. The appearance of such conventional gratings for windows/doors are monotonous which decreases the utility of the windows/doors. Therefore, it is desirable to develop gratings for windows/doors consisting of integrally formed and durable members that can be easily assembled and can give the windows/doors changeful appearance.